#include<iostream>
using namespace std;
class Box
{
private:
    double length;
    double breadth;
    double height;
public:
    Box(/* args */)
    {

    }
    ~Box()
    {

    }
    double getVolume(void)
    {
        return length*breadth*height;
    }
    void setLength(double len)
    {
        length=len;
    }
    void setBreadth(double bre)
    {
        breadth=bre;
    }
    void setHeight(double hei)
    {
        height=hei;
    }
    Box operator+(const Box& b)
    {
        Box box;
        box.length=this->length+b.length;
        box.breadth=this->breadth+b.breadth;
        box.height=this->height+b.height;
        return box;
    }
};
int main()
{
    Box box1,box2,box3;
    double volume=0;
    box1.setLength(1);
    box1.setBreadth(1);
    box1.setHeight(1);

    box2.setLength(2);
    box2.setBreadth(2);
    box2.setHeight(2);
    volume=box1.getVolume();
    cout<<"volume of box1:"<<volume<<endl;
    volume=box2.getVolume();
    cout<<"volume of box2:"<<volume<<endl;
    box3=box1+box2;
    volume=box3.getVolume();
    cout<<"volume of box3:"<<volume<<endl;
    return 0;
}